Lead removal device



22, 1964 A. H. THOMAS ETAL 3,162,518

LEAD REMOVAL DEVICE Filed July 24, 1965 2, Sheets-Sheet 1 ELECTRIC MOTORFIG. 1

INVENTORS A. a. THOMAS w. s. amass D. s. HENDERSON ATTORN D 1964 A. H.THOMAS ETAL 2,

I LEAD REMOVAL DEVICE Filed July 24, 1963 2 Sheets-Sheet 2 II II I FIGAFIGS

INVENTORS A. H. THOMAS w. s. amss'si D. S. HENDERSON ATTORN UnitedStates Patent 3,162,518 LEAD REMGVAL DEV TUB Alan H. Thomas, Laurel,Warren S. Briggs, fiiiver Spring,

and Donald 8. Henderson, Baltimore, Md assignors to W. R. Qrace 6: Co,New York, N311, a corporation of Connecticut Filed July 24, 1963, Ser.No. 297,434 1 Claim. (Ci. Si -315) This invention relates to a devicefor physically separating lead from auto exhaust gases.

The problem of air pollution has been the object of much study in recentyears. It has been found that in completely burned exhaust gases fromautomobiles are a major contributor to the pollution problem. Muchresearch is being directed toward finding a method which will ensurecomplete oxidation of auto exhaust gases before they escape to theatmosphere. One of the most obvious and satisfactory methods foraccomplishing this is to pass the incompletely burned gases over anoxidation catalyst thus obtaining complete combustion. However, asignificant obstacle to this solution is presented by the lead presentin gasoline. The majority of gasoline contains tetraethyl lead as ananti-knock additive. However, it is well known that lead is a catalystpoison. The lead in automobile exhaust quicldy poisons and rendersuseless oxidation catalysts which would otherwise be efiective inpromoting complete combustion of auto exhaust gases. it would bedesirable to somehow separate the lead from the auto exhaust before itreaches the oxidation catalyst.

It is an object of this invention to provide a means whereby lead inauto exhaust gases is physically separated from the gases before theyare passed to the catalytic oxidation treatment.

It is another object to provide a device which can be used inconjunction with other lead removal means for increased efiiciency.

It is a further object of this invention to remove both metallic leadand soot particles from the combustion gases of internal combustionengines.

The invention is illustrated by the accompanying drawing in which:

FIG. 1 is a side elevational view showing the device inserted in theexhaust system of a single cylinder engine;

FIG. 2 is a top view of the device;

FIG. 3 is a side elevational view of the device in combination with amechanical lead removal device, and

PEG. 4 is a side elevational view showing the device inserted in astandard auto exhaust system.

Referring to FIG. 1, engine supplies the products of combustion via line11 to cyclone device 12. The gases pass downward through outer chamber12 then up through lead adsorbent bed 13 and out line 15 into aconventional mutfier device 16 containing a catalytic oxidation bed 17.

FIGURE 2 shows the path of the gases entering chamber 12 via line 11,entering bed 13 and exiting via line 15.

FIGURE 3 shows a modification of the device where exhaust gases passinto chamber 12 via line 11, pass downward around chamber 12 and upthrough bed 13. Part of the gases pass through trap 14 and out throughopening 21, then are carried by line 22 to a mechanical lead removaldevice 13 where additional lead is removed. The gases then pass via line19 to line 15 where they join the remainder of the gases which pass upthrough bed 13 and out via line 15 to the catalytic convertor.

3,152,518 Patented Dec. 22, 1964 FIGURE 4 shows automobile engine 23from which exhaust is directed via line 11 to cyclone device 12. Theexhaust passes down the outer chamber of device 12, up through leadadsorbent bed 13, out via line 15 into a conventional mufiler device 16containinga catalytic oxidation bed.

In operation, gases from engine 16 enter the cyclone 12 through line 11.The gases are directed downward by bailie 2t} and swirled throughchamber 12 depositing lead on the walls of the chamber. The motion ofthe gases causes the deposited lead to fall into trap 14. The gases thenpass upward through lead adsorbent bed 13. The lead free gases then passout of the cyclone via line 15 into the muiller system. As shown in FIG.1, the device is placed on the downstream side of the manifold in such aposition that the gases leaving the manifold pass through the leadremoval device before going to any other unit. A convenient modificationof this arrangement is to allow the gases to pass through a bed of leadadsorbent material and then into the cyclone. If this modification ischosen, the bed of lead adsorbent material in the cyclone can beeliminated if desired.

The lead adsorbent can be any of the well-known materials suitable forthis purpose. Suitable substances include, for example, silica-alumina,alumina and alumina impregnated with salts of copper, sodium, molybdenumand vanadium.

This system is especially advantageous in that it can control the heatrequired in the gases for satisfactory operation of the catalyticconvertor. When the gases reach the catalytic converter, they should behot enough to allow quick warm-up of the catalyst bed so that theoxidative conversion will reach maximum efficiency in a very short time.However, the gases should not be too hot since this causes rapiddeterioration of the catalyst. By using temperature controlling means inconjunction with the device, the gases can be directed to the catalyticconverter at any desirable temperature.

What is claimed is:

A device for removing lead particles from auto exhaust gases comprisinga source of auto exhaust gases containing lead particles, a cyclonechamber, means for introducing said gases into said chamber in adownward rotational flow pattern, a trap attached at the bottom of saidcyclone chamber having an exit aperture in its bottom surface, aninverted cone-shaped lead adsorbent bed extending through the centralportion of said chamber from above said trap to an exit aperture at thetop of said chamber, a means for directing exhaust from said top exitaperture of said chamber to a conventional automobile mufiler system, ameans for directing exhaust from said exit aper ture at the bottom ofsaid trap to a mechanical lead removal device containing an exitaperture and a means for directing exhaust from said mechanical deviceto a conventional automobile mufller system.

References tilted by the Examiner UNITED STATES PATENTS 1,513,035 10/24Donaldson 55-329 1,716,481 6/29 Bilsky.

2,642,951 6/53 Norton 55-316 X 3,013,628 12/61 Jacobs et al. 3,016,1081/62 Myddelton 55-337 3,056,662 10/62 Ridgway.

REUBEN FRIEDMAN, Primary Examiner.

